Installed a Holly Blue LP, with the Regulator, could not get above 11 psi
with adjustment maxed out, Removed the regulator and streached the
bypass spring on the pump, max pressure 13.5 with some spikes above
15 psi ( cold start ) than smoothes out, But do get spikes when loading and unloading the engine ( smarty sw5 ) ( lowest FP 10 psi ).

Note: Do have a big line kit installed, & Pump is mounted by tank
Also Relay controlled...

?1: Do I need the regulator,

?2 If so, How can I get more pressure from the regulator

?3 Will the pressure spikes hurt the IP

AND, All Holly blue install info would welcome..

 

i have a holley blue installed and am not using a regulator, runs 14lbs at idle all i can pull it down to is 11lbs pulling 15-16,000. try bypassing the regulator and see what you get

 

yup take out the regulator and just stretch the spring to get what pressure you want. i had to stretch/compress mine a couple times to get it dialed in just right. the regulator is more for carburated motors.

 

exactly . same deal here! and then i threw the regulator away . didnt want it.

 

ok, regulator out, spring adjusted. ( running smarty sw 5 )

13.5 at idle increases to 14 psi after trucks runs a few minutes.
runs about 13 psi at normal cruise

drops to about 11 psi than kicks up to 13 psi ~
and stays there until throttle released,
Than spikes to 15-17 psi and back to 13 psi...

?? I assume the bypass is regulating at 13 psi, and the drop in pressure
closes the bypass and brings pressure back up 13-14 under load,
and also the spike is the restricted pressure when throttle is closed,
than back to regulating at 13 psi.

??? any comments as to above ,
Also will the spike in fuel pressure hurt the VP44.

 

I'm running a Holley Blue as well and keep getting the pressure fluctuations. It's driving me nuts. There's no rhyme or reason to when it happens. Sometimes at idle, sometimes at a steady cruise. But like you, it goes away when you add more coal in the engine room. Thinking of moving the stock LP down there and replacing the Blue to see what happens. The stocker didn't go bad, I just did a relo and used the Blue because it's readily available.

 

where is this spring you talk about and how does it need to be adjusted? My FP at idle is about 12.5 and it doesnt go below 9.5. i wouldnt mind seeing 14 again I'm running a big line kit, would that make a big difference?

 

BIG screw on side of pump housing, remove screw, spring comes out.

Stretch it, re install,

Be carefull easier to strech than compress,,

 

You can also buy bigger springs that will increase the pressure from 12psi to 19psi (as advertised). You should be able to get the from Maryland Performance, where you got the pump. Part # Moroso 65770. Less than $10

 

After I installed my Holley it was also eratic on pressure I finally discovered that the pressure reilef plunger was installed backwards. The pump was new from Jeggs. Anyway installing it in the proper direction made the pump delivery steady. I am using the Morso high pressure spring 16 PSI idle 14 cruse 13 WOT

 

whats the problem...you got plenty of pressure

 

Well the relief plunger is in the right way. Once I burn some fuel out I'll take the pump out and see if it's sucked some trash into the intake.

Did I mention these pressure fluctuations are driving me insane?

 

I assume you installed rubber fuel hoses...
Pinch the lines with visegrips , clamps, whatever( just enough to close the lines)
won't ;lose much fuel or get too much air in system...Mine still fluctuates, but seems to be getting better, was worried about the spike in FP
above 15 psi, but no one else seems excited.
so NOT TO WORRY...

 

I am using a bypass valve

look here https://www.dieseltruckresource.com/...=170582&page=2

 

Thanks, what kind and where did you get it , and also how much $$$$$